ICD-10 Code H70.003 – Acute mastoiditis without complications, bilateral (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code H70.003 – Acute mastoiditis without complications, bilateral
What it is
H70.003 identifies acute mastoiditis affecting both mastoid processes without documented complications. It refers to an acute infection or inflammation of the mastoid air cells behind each ear.
Clinical signs
Typical findings include ear pain, fever, postauricular tenderness, and swelling or redness behind the ear. Clinical features vary; refer to documentation, especially for evidence of bilateral involvement and absence of complications.
When to use this code
Use this code when the provider documents acute mastoiditis in both ears and specifically states there are no complications. It is appropriate for confirmed bilateral disease in an acute setting. Check documentation if the record mentions abscess, intracranial spread, or chronic mastoid disease.
Do not use for
Do not use H70.003 if mastoiditis is unilateral, chronic, or described with complications. Also avoid it when the documentation only notes ear infection or mastoid pain without a confirmed diagnosis.
Coding tip
Verify laterality and the phrase “without complications” in the provider note before assigning H70.003.